Food Bacteria Research Articles

Identification of the chemical profile and evaluation of the antimicrobial effect of Eryngium billardieri Delar essential oil component against bacterial species of agricultural and food interest.

Studies on the antibacterial activity of the essential oil of E. billardieri are limited. In this study, we identified this herb as a natural complex effective against several bacteria by employing disk diffusion and broth microdilution susceptibility methods. Primary estimation of the antimicrobial effect of this herbal compound by disk diffusion method showed that the oil could inhibit the growth of the tested bacteria by the appearance of haloes between 8.25 and 21.25 mm. In the next step, the oil was found to be active against all 24 tested Gram-negative and Gram-positive bacteria in the broth media, at minimum inhibitory concentrations ranging from 0.67 to 34.17 g L-1. Furthermore, Enterococcus faecalis and Curtobacterium flaccumfaciens pv. flaccumfaciens were the most sensitive food and plant pathogenic bacteria, respectively. Gas chromatography-mass spectrometry analysis was conducted to assign the ingredients present in the oil; 34 different components representing 95.71% of the total oil were identified, with n-hexadecanoic acid being the dominant component, followed by 2-Pentadecanone, 6,10,14-trimethyl, 1H-Indene, 1-ethylideneoctahydro-, and Cinnamyl tiglate. These findings demonstrate, for the first time, a broad spectrum of the antibacterial capacity of E. billardieri. Based on these observations, the oil could be applied as a natural preservative with the potential for designing novel products. Its bioactive agents can also be isolated for further use in the food and agricultural industries.

Deteksi Molekuler Bakteri Patogen pada Makanan Fermentasi Tempe Dage berdasarkan marka gen 16S rRNA

Tempe Dage is fermented food product originating from Banyumas Regency, Central Java. The appearance of Dage tempeh is slightly different from tempeh in general with lots of black spots on its surface. Even though it is often consumed by the people of Banyumas, there is no information regarding the presence of pathogenic bacteria in Dage tempeh which have the potential to harm human health. Therefore, this study aims to detect the diversity of pathogenic bacteria in the Tempe Dage microbiome using the Next Generation Sequencing (NGS) approach. The research steps were from bacterial culture with Reasoner’s 2A (R2A) medium, genomic DNA extraction, Ilumina platform-based sequencing based on the Variable region of the 16S rRNA gene, and bioinformatics analysis. The results of bioinformatics analysis on the EZBioCloud webserver (https://www.ezbiocloud.net/contents/16smtp) showed that the Dage tempe samples contained several pathogenic bacteria which were detected, such as Escherichia coli, Enterococcus faecalis, Staphylococcus aureus, Vibrio metschnikovii and Salmonella bongori. These results provide novel information regarding the presence of pathogenic bacteria in traditional Dage food which can be further analyzed using a conventional culture approach.

Intestinal Barrier Dysfunction in Inflammatory Bowel Disease: Underpinning Pathogenesis and Therapeutics.

The intestinal barrier is composed of several essential elements including luminal enzymes, bile acids, water layer, epithelial layer, and enterocyte layer. It acts as a dynamic interface between the luminal contents of food, commensal and pathogenic bacteria, and the gastrointestinal tract. The role of barrier dysfunction is of significant research interest in the development and targeted treatment of chronic inflammatory gastrointestinal conditions, such as inflammatory bowel disease. This review aims to examine the role of intestinal barrier dysfunction in the development of inflammatory bowel disease, the pathophysiology of increased barrier permeability in inflammatory bowel disease, and to explore potential treatment targets and clinical applications.

The Benefits of Probiotics on Oral Health: Systematic Review of the Literature.

Aim: Probiotic microorganisms, commonly used to bolster gut health, might also have benefits for dental health, according to certain studies. Probiotics (PBs) are associated with reducing cariogenic pathogens and protecting against periodontal diseases, although the exact way they function in the mouth is not fully clear. Our study aimed to explore the use of PBs to improve oral health, focusing on issues such as cavities, gum disease, bad breath, mucositis, and periimplantitis. Materials and Methods: We utilized the Boolean keywords "Probiotics" AND "Oral health" to search the databases of PubMed, Scopus, and Web of Science. The search was restricted to English-language papers published from 1 January 2019 to 13 April 2023. Results: A total of 3460 articles were found through our computerized search. After removing duplicates, reviewing the papers, and determining their relevance, 12 were selected for inclusion. Conclusions: Assessing how bacteria in food or dietary supplements might alter the stable oral microbiota is a complex task. Although probiotic microorganisms have been found to have proven therapeutic benefits, their application in dental health is not yet solidly backed by evidence. Further research is necessary to thoroughly understand the long-term effects of probiotic bacteria on the oral environment, including their ability to colonize and form biofilms.

Antibacterial inhibitory test of tomi-tomi fruit (Flacourtia iinermis Roxb) extracts against pathogenic bacteria in improving food safety

The tomi-tomi fruit (Flacourtia inermis Roxb) is a rare plant. This fruit has benefits as a flavourings spice and also traditional medicine used by the community, besides it also contains tannins and flavonoid compounds that can inhibit the growth of pathogenic bacteria in food. To support the use of tomi-tomi fruit (F. inermis Roxb) and increase its application in supporting food safety, the purpose of this study is to test and see the antibacterial inhibitory power of tomi-tomi fruit extract against pathogenic bacteria, namely Gram-Negative bacteria (Salmonella typhimurium) and Gram-Positive bacteria (Staphylococcus aureus and Bacillus cereus). This study is an experimental study using the Disc Diffusion method to determine the inhibitory power of bacterial growth using ethanol solvents with concentrations of 25%, 50%, and 75%. The results showed that of the three concentrations of tomi-tomi fruit extract tested against pathogenic bacteria, it turned out that the ethanol extract concentration of tomi-tomi 75% had a very strong inhibitory power category in S. aureus bacteria of 39 mm, S. typhimurium of 32.7 mm and B. cereus of 34.0 mm. Thus, tomi-tomi fruit ethanol extract has an inhibitory power that can be used for decontamination of 3 types of bacteria, especially in Staphylococcus aureus bacteria which have very strong inhibitory power, to maintain quality and improve food safety, among others rice, milk, cheese, fish, and meat that is often contaminated.

Foodborne Diseases - A Public Health Challenge

+Foodborne diseases are caused by consuming foods contaminated with toxic chemicals or biotoxins or foods containing bacteria, viruses, fungi, parasites, or foods containing bacteria, viruses, fungi, or parasites. Foodborne infections are a major global health problem that causes substantial morbidity and mortality around the world. Each year, over 600 million people are affected by foodborne diseases. Children under five years are particularly at a high risk comprising 30% of the total foodborne deaths annually. Foodborne diseases are classified as foodborne infection, foodborne intoxication and foodborne toxic infection. Ingestion of viable pathogens like bacteria, viruses, parasites and protozoa along with the food leads to food infection. Ingestion of preformed toxins, previously generated by bacteria in food, are causes foodborne intoxication. Staphylococcal intoxication and botulism are some examples of food intoxication. Foodborne toxic infection is caused by microorganisms that create toxins in situ after being eaten with food, infecting the intestine. Cholera, listeriosis and Clostridium perfringens gastroenteritis are some examples of toxic infections. Foodborne diseases can be prevented by proper sanitation and hygiene, using safe raw materials and using the right temperature to prepare and store food. Safe food handling practices can be ensured by following HACCP (Hazard Analysis and Critical Control Point) and FSSAI (Food Safety and Standards Authority of India) guidelines. Foodborne disease will continue to be a major hazard around the world, but with effective sanitation and hygiene, prevention is not difficult.

Role and importance of lactic acid bacteria in different Indian fermented foods

Role and importance of lactic acid bacteria in different Indian fermented foods

A model of antibiotic resistance genes accumulation through lifetime exposure from food intake and antibiotic treatment.

Antimicrobial resistant bacterial infections represent one of the most serious contemporary global healthcare crises. Acquisition and spread of resistant infections can occur through community, hospitals, food, water or endogenous bacteria. Global efforts to reduce resistance have typically focussed on antibiotic use, hygiene and sanitation and drug discovery. However, resistance in endogenous infections, e.g. many urinary tract infections, can result from life-long acquisition and persistence of resistance genes in commensal microbial flora of individual patients, which is not normally considered. Here, using individual based Monte Carlo models calibrated using antibiotic use data and human gut resistomes, we show that the long-term increase in resistance in human gut microbiomes can be substantially lowered by reducing exposure to resistance genes found food and water, alongside reduced medical antibiotic use. Reduced dietary exposure is especially important during patient antibiotic treatment because of increased selection for resistance gene retention; inappropriate use of antibiotics can be directly harmful to the patient being treated for the same reason. We conclude that a holistic approach to antimicrobial resistance that additionally incorporates food production and dietary considerations will be more effective in reducing resistant infections than a purely medical-based approach.

Detection of Escherichia coli by capillary electrophoresis assisted by large volume sample stacking and nicking endonuclease signal amplification

Efficient, accurate and economical detection of pathogenic bacteria is crucial in ensuring food safety and preventing foodborne illnesses. In this study, a capillary electrophoresis coupled laser-induced fluorescence assay (CE-LIF) was developed for the detection of Escherichia coli (E. coli) by detecting its specific DNA. The CE-LIF was assisted by both online enrichment and offline amplification to improve the detection sensitivity of bacterial DNA. Here the online amplification was performed by large volume sample stacking (LVSS), while the offline amplification was nicking endonuclease signal amplification (NESA). Under the optimal experimental conditions, the detection limit of bacterial target DNA was 2.5 fM, and the conversion concentration of E. coli was 3 CFU · mL−1. The method had been applied to the detection of commercially available skim milk samples with good results, which proved that it could be used as an effective tool for food and environmental bacteria monitoring.

The Effect of Bibliotherapy in Teeth-brushing Behavior to Prevent Dental Caries Among Pre-School Children

Background: Dental caries is a dental disease caused by the presence of food residue and bacteria for a long time, where the bacteria produce acid which can cause tooth decay. In order for preschool-aged children to prevent tooth decay, bibliotherapy is needed which can provide insight and change the behavior of preschoolers. Bibliotherapy is using a story to start a discussion about a problem and it should be used as an alternative to problem solving. Purpose: To determine the effect of bibliotherapy on tooth brushing behavior for the prevention of dental caries in preschool children at one of kindergarten in South Jakarta, Indonesia. Method: This study used quasi-experimental design with pre-test and post-test design, where the intervention group is measured or observed before and after the intervention. The research sample consisted of 30 respondents. The sampling technique uses total sampling. The research instrument is a tooth-brushing behavior questionnaire. Data analysis used the Wilcoxon test to determine the effect of bibliotherapy on tooth-brushing behavior. Results: The behavior of the respondents before the intervention showed that the behavioral variable with good category was 13.3% and after the intervention showed that the variable with good behavior increased to 96.7%. The results of the study obtained a p value of 0.000 <0.05 which indicates that bibliotherapy has an effect on tooth-brushing behavior. Conclusion: There is an effect of bibliotherapy on tooth-brushing behavior to prevent dental caries in preschool children in one of kindergarten in South Jakarta.

Chemical composition and antioxidant/antibacterial depictions of Zahidi date palm (Phoenix dactylifera) kernel Oil

Date palm “Phoenix dactylifera” variety Zahidi is a unique well-known cultivar. Mature fruits are semi-dry, medium size, cylindrically shaped and golden brown. However, there are three stages to harvesting the dates soft, hard or semi-soft. In this research, the oil processed from the seed/kernel of the date palm Zahidi is chemically analysed for its composition, antioxidant capacity and its antibacterial properties were investigated. Date seeds were ground and extracted for the oil. Wet chemical analyses were implemented on the extracted oil via various analytical techniques such as high-performance liquid chromatography (HPLC) and gas chromatography-mass spectrometry (GC–MS). Oil fractions of ethanol, methanol and acetone were tested for antibacterial activity, which was evaluated employing the Kirby–Bauer disc-diffusion method. Antibacterial action was examined for four bacterial strains; two of them representing Gram-positive such as Bacillus subtilis, and Staphylococcus aureus, and the other two for Gram-negative such as Pseudomonas aeruginosa and Escherichia coli. The antibiotics tetracycline, chloramphenicol, streptomycin, gentamycin and vancomycin were used as positive standards. The Minimum Bactericidal Concentration (MBC) and Minimum Inhibitory Concentration (MIC) of the bacterial strains were tested and evaluated. The antioxidant activity was evaluated as free-radical scavenging capacity (RSC) towards 2,2 - diphenyl -1-picrylhydrazyl (DPPH) radicals for the methanol fraction (MF), remaining lipid fraction (LF) and non-fractioned oil, i.e., the total fraction (TF). The RSCs for the MF, LF and TF were 42.5, 9.1 and 68.3, respectively. Zahidi seed/kernel oil extract inhibited all of the test microorganisms, with MICs that ranged from 10 to 42 mg/mL and MBCs were found to be ranged between 21 and 167 mg/mL. These outcomes suggest that the extracts could be developed as a foundation of expected antimicrobial complexes to fight unwanted bacteria in foods. Overall, the results showed that the oil is suitable for food, cosmetics, personal care products and pharmaceuticals.

Fermented Foods as a Potential Vehicle of Antimicrobial-Resistant Bacteria and Genes

Fermented food products are widely consumed for their nutritional and health-promoting properties, earning them a central place in diets around the globe. However, these foods can present a paradox, as they have the potential to harbor not only beneficial probiotics but also antibiotic-resistant (AR) microbes and genes. The impact of AR microbes and genes in fermented foods has far-reaching implications, such as potential effects on human health, repercussions in the food industry, and environmental consequences. An in-depth analysis of AR microbes and genes in fermented foods, including dairy products, fermented fruits and vegetables, meat products, and beverages, would provide insights into the extent and ramifications of the issue with these foods. Therefore, this review systematically presents the status of AR in fermented foods, with a particular focus on AR bacteria and genes within this category of food products. The review also highlights the complexities of AR in fermented foods, emphasizing the role of bacterial adaptation during the fermentation process and the dynamics of bacterial gene transfer. Various factors contributing to AR microbes and genes are brought into focus, including intrinsic resistance among bacteria in fermented foods and the potential risk of contamination with pathogenic bacteria. Moreover, this review presents a range of mitigation strategies, from the development of novel antimicrobials to advances in fermentation technology and regulatory control. This comprehensive perspective on the intricate interplay between AR and fermented food will potentially pave the way for more targeted research and mitigation strategies in this critical area.

A robust nanoLC high-resolution mass spectrometry methodology for the comprehensive profiling of lactic acid bacteria in milk kefir

Consumer attention to functional foods containing probiotics is growing because of their positive effects on human health. Kefir is a fermented milk beverage produced by bacteria and yeasts. Given the emerging kefir market, there is an increasing demand for new methodologies to certify product claims such as colony-forming units/g and bacterial taxa. MALDI-TOF MS proved to be useful for the detection/identification of bacteria in clinical diagnostics and agri-food applications. Recently, LC-MS/MS approaches have also been applied to the identification of proteins and proteotypic peptides of lactic acid bacteria in fermented food matrices.Here, we developed an innovative nanoLC-ESI-MS/MS-based methodology for profiling lactic acid bacteria in commercial and artisanal milk kefir products as well as in kefir grains at the genus, species and subspecies level. The proposed workflow enables the authentication of kefir label claims declaring the presence of probiotic starters. An overview of the composition of lactic acid bacteria was also obtained for unlabelled kefir highlighting, for the first time, the great potential of LC-MS/MS as a sensitive tool to assess the authenticity of fermented foods.

Fiber-Optic-Based Biosensor as an Innovative Technology for Point-of-Care Testing Detection of Foodborne Pathogenic Bacteria To Defend Food and Agricultural Product Safety.

Food safety is a concerning issue globally. Foodborne-pathogenic-bacteria-derived foodborne disease outbreaks have increased the threat to human health. The accurate and rapid detection of foodborne bacteria is of great significance for food safety. A fiber-optic-based biosensor has emerged as a powerful technique for the point-of-care testing of foodborne bacteria in food and agricultural products. This Perspective discusses the opportunities and challenges of fiber-optic-based biosensors for foodborne bacteria detection. The corresponding solution strategies to promote the application of this innovative technology in food and agricultural product detection for food safety and human health are also discussed and proposed.

Tannic acid-layered hydroxide salt hybrid: assessment of antibiofilm formation and foodborne pathogen growth inhibition.

Pathogenic bacteria in food are a public health problem worldwide. Polyphenolic bioactive compounds with antimicrobial activity and antioxidant capacity represent a tangible alternative to overcome this problem. To preserve the biological functions of phenolic compounds such as tannic acid, which has been described to possess antioxidant and antimicrobial activity, this study describes the synthesis of a zinc nanohydroxide to stabilize its properties. Characterization by XRD, FT-IR, SEM, DLS, and UV-vis evidenced the presence of tannic acid in the nanohybrid TA-Zn-LHS which was further confirmed by DPPH, ABTS and FRAP antioxidant activity techniques. Bacterial growth inhibition of Escherichia coli ATCC 8739, Salmonella Enteritidis, and Staphylococcus aureus ATCC 25923 was over 80% at 50mg/mL of the TA-Zn-LHS and over 90% with Zn-LHS. Antibiofilm evaluation of these same strains showed biofilm formation inhibition > 90% and > 80% for Zn-LHS and TA-Zn-LHS, respectively. The toxicity evaluation of the materials in Artemia salina showed a classification of the materials as non-toxic to slightly toxic in concentrations up to 1mg/mL. These results allow us to introduce a new nanohybrid useful for food safety with safe biological functions.

Potential of Red, Brown, and Green Macroalgae from Dato Beach, Majene, Indonesia as Natural Food Preservative

Macroalgae is one of the natural resources present in Indonesian coastline areas – specifically in Dato Beach, Majene, South Sulawesi. The abundance of macroalgae found in Dato Beach can be utilized in various sectors – including health, cosmetics, and food. The aim of this study was to investigate the secondary metabolites of three types of macroalgae in Dato Beach and their potential to inhibit the growth of pathogenic bacteria in food. The three macroalgae utilized in this study were Turbinaria decurrens (brown algae), Galaxaura rugosa (red algae), and Halimeda opuntia (green algae) representing the three groups of macroalgae based on their dominant pigments. Four types of pathogenic bacteria – namely, Staphyloccus aureus and Bacillus cereus as Gram-positive bacteria plus Salmonella typhi and Escherichia coli as Gram-negative bacteria – were collected from the Biology Laboratory at Universitas Sulawesi Barat, as these bacteria are commonly responsible for food spoilage. The study began with a sampling of macroalgae, followed by cleaning and drying, and subsequently extraction using methanol as the solvent. Methanol was chosen as the universal solvent for its ability to extract both polar and nonpolar components. Phytochemical screening was carried out to test for the presence of flavonoids, steroids/terpenoids, and alkaloids, which represent the three groups of secondary metabolites. The antimicrobial test was carried out using the well diffusion method, as a control used 80 ppm of ampicillin. The results of the study indicated that T. decurrens contains flavonoids, steroids, and alkaloids, G. rugosa contains flavonoids, terpenoids, and alkaloids, whereas H. opuntia only contains terpenoids and alkaloids. Furthermore, G. rugosa was found to have the best ability to inhibit bacteria, with an inhibition zone ranging from 22–23 mm; in some treatments, the diameter of the inhibition zone was even larger than the positive control. T. decurrens was only effective in inhibiting the growth of S. aureus, whereas H. opuntia demonstrated the potential to inhibit the growth of S. aureus and E. coli, and for B. cereus and S. typhi, it could only be inhibited by 100% (1000 μL) extract of the H. opuntia extract.

Rapid and sensitive detection of E. coli O157:H7 by lateral flow immunoassay and silver enhancement

The aim of this study was to develop a sensitive lateral flow immunoassay (LFIA) for the rapid detection of Escherichia coli (E. coli) O157:H7, a pathogen contributor to diseases and fatalities worldwide. Au nanoparticles with high stability, uniform size, and shape were synthesized and coated with heterobifunctional PEG polymer with carboxyl groups, and they were bioconjugated to be used as label in sandwich-LFIA. Then, a silver enhancement strategy was developed as an accessible, rapid, and cost-effective approach for signal amplification to reduce the limit of detection (LOD). The optimal results were achieved when a solution of silver nitrate and hydroquinone/citrate buffer was added to the strips for 4 min. This led to a decrease in the visual LOD from 2 × 106 (CFU mL−1) to 2 × 103 (CFU mL−1), resulting in a threefold improvement in sensitivity compared to the conventional LFIA system. The specificity of the system was evaluated by using non-target bacteria (E. coli BL21 and E. coli T515) and its reliability was determined by testing commercial food samples (milk, tap water, and orange juice), demonstrating its effectiveness for quickly detecting pathogenic bacteria in food products.Graphical

Biological control of foodborne pathogens by lactic acid bacteria: A focus on juice processing industries

The use of lactic acid bacteria (LAB) in foods as biocontrol agents against foodborne pathogens has become increasingly known. Under the premise that controlling the adhesion of microorganisms to food contact surfaces is an essential step for meeting the goals of food processing, the aim of this work was to investigate the inhibitory and anti-biofilm effectiveness of Lactobacillus rhamnosus GG (ATCC 53103) and Lactobacillus casei (ATCC 393) against Escherichia coli O157:H7, Salmonella enterica and Listeria monocytogenes. Lactobacillus strains (108CFU/ml) and pathogens (104CFU/ml) were evaluated to monitor LAB anti-adhesive and antibiofilm effect, in two main scenarios: (i) co-adhesion and (ii) pathogen incorporation to stainless steel surfaces with a protective biofilm of Lactobacillus cells. In (i) the predominant effect was observed in L. rhamnosus against S. enterica and L. monocytogenes, whereas in (ii) both LAB significantly reduced the number of pathogenic adherent cells. The effect of pre-established LAB biofilms was more successful in displacing the three pathogens than when they were evaluated under co-adhesion. These findings show that both LAB can be considered good candidates to prevent or inhibit the adhesion and colonization of L. monocytogenes, S. enterica and E. coli O157:H7 on surfaces and conditions of relevance for juice processing industries, offering alternatives for improving the safety and quality of fruit-based products.

Transcriptome analysis reveals the tetracycline resistance mechanism of Lacticaseibacillus rhamnosus FXJWS19L2 and Lacticaseibacillus paracasei FQHXN23L6

Lacticaseibacillus rhamnosus and Lacticaseibacillus paracasei are widely used and regularly consumed probiotics. However, before they are used in food, safety evaluation of antibiotic resistance should be performed to assess the risk of transferring resistance genes. Our study found that L. rhamnosus FXJWS19L2 and L. paracasei FQHXN23L6 exhibited a high tetracycline resistance phenotype but did not contain any known tetracycline resistance genes in their genomes. To investigate the molecular mechanisms underlying tetracycline resistance in these two strains, we performed a transcriptomic analysis combined with gene overexpression techniques to explore potential resistance genes and validate their functions. The transcriptome analysis identified 963 and 372 differentially expressed genes (DEGs) in L. rhamnosus FXJWS19L2 and L. paracasei FQHXN23L6, respectively, after tetracycline induction. The DEGs in these two strains were mainly involved in ribosomal protein synthesis, ABC transporters, and the metabolism of many substances. Moreover, the overexpression of the most significantly up-regulated gene (yjcA), which encodes an ABC transporter, improved the resistance of bacteria to tetracycline. This study reveals the resistance mechanism of these two strains to tetracycline and provides a theoretical reference for the safe application of this type of lactic acid bacteria in food.

Best Practices in Oral Care.

Best Practices in Oral Care.